I. Field
The present disclosure relates generally to communication, and more specifically to techniques for transmitting data in a wireless communication system.
II. Background
A wireless multiple-access communication system may include many Node Bs (or base stations) that support communication for many user equipments (UEs). A Node B may communicate with multiple UEs on the downlink and uplink. The downlink (or forward link) refers to the communication link from the Node Bs to the UEs, and the uplink (or reverse link) refers to the communication link from the UEs to the Node Bs.
On the downlink, a Node B may transmit data to multiple UEs using dedicated data channels and/or a shared data channel. A dedicated data channel is a data channel that is assigned to a specific UE and is used to send data only to that UE. A shared data channel is a data channel that is shared by multiple UEs and can carry data for one or more UEs at any given moment. A data channel is a mechanism for sending data and may be dependent on the radio technology used by the system. For example, in a Code Division Multiple Access (CDMA) system, a data channel may be associated with a specific channelization code, e.g., a specific Walsh code.
A Node B may use a shared data channel to achieve various benefits. The shared data channel may allow for better utilization of the available radio resources since each UE may be served as needed and using just enough radio resources to serve that UE. The shared data channel may also support higher peak data rates for the UEs since all radio resources available for the shared data channel may potentially be used for one UE. The shared data channel may also provide flexibility in scheduling the UEs for data transmission on the downlink.
A Node B may send signaling on a shared control channel in parallel with the shared data channel to convey how the shared data channel is used. For example, the signaling may convey which UE(s) are being served, the radio resources allocated to each UE being served, how data is sent to each UE, etc. Because of the dynamic nature of the shared data channel, the UEs that can potentially receive data on the shared data channel may continuously monitor the shared control channel in order to determine whether data is being sent for them. Each UE that receives signaling on the shared control channel may process the shared data channel based on the received signaling to recover the data sent to the UE. The shared control channel represents overhead for the shared data channel.